JP2792616B2 - Press forming equipment for optical elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element press-forming apparatus used for forming a high-precision optical element such as an aspherical lens by press molding.

[0002]

2. Description of the Related Art In recent years, attention has been paid to a method of directly press-molding a softened glass material for optical use in a molding die instead of a method of processing an optical element by grinding and polishing.

[0003] Usually, in this type of molding, a glass material in a softened state is pressed by using a molding die member that slides in the barrel die in the barrel die, and the molding surface corresponding to the molding surface of the die member is pressed. An optical element press molding apparatus is used in which the optical function surface is formed on the glass material. What is important here is that, in order to obtain the required optical precision, the amount of lowering of the upper mold member during press molding must be set strictly so that the optical element is molded with a high precision thickness. That is. Therefore, a space for adjustment is provided between the upper mold member and the body mold.
Is equipped.

On the other hand, in order to improve work efficiency, a plurality of pairs of upper and lower mold members are arranged in one body mold, and these are operated by a common press operation mechanism to simultaneously form a plurality of optical elements. It has been proposed to configure a press molding apparatus so that a molded article can be obtained.

[0005]

However, in the above-described molding apparatus, when each of the upper mold members is lowered by a common operating member in the press molding process, a dimensional error between the operating member and each of the upper mold members may occur. , It is not possible to reliably lower all the upper mold members by a predetermined amount, or excessive load is applied to any of them, causing poor sliding during hot, galling and damaging the upper mold members, etc. There is a problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above-mentioned circumstances, and is provided with at least a plurality of pairs of mold members for a common body mold, and the upper mold members are slid to move the glass material. In the case of press molding, regardless of the dimensional error, the upper mold member is lowered by a predetermined amount to maintain the thickness of the molded product with high accuracy, and the continuous press molding of the optical element can be efficiently performed. An object of the present invention is to provide an optical element press molding apparatus which can be manufactured and has good productivity.

[0007]

Therefore, in the present invention,
Put the glass material in each of a plurality of molding dies, and press the mold members of each molding die individually by a common pressing means,
In a molding device for molding an optical element, the mold members of the respective molding dies are slidably disposed on a common body die, and a pressing operation member corresponding to each of the upper mold members of the respective molding dies is shared. The holding block is provided with a separate elastic mechanism for individually applying a downward elastic force to the pressing operation member, and the pressing operation member is provided in the holder block. When the holder block is lowered to apply a pressing pressure, each flange portion of the upper die member is at least abutted against the top of the body die, and each elastic holding mechanism operates. I do.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIGS. 1 and 2, the illustrated press forming apparatus loads a glass material (glass blank) into a forming die 1 and operates a press operation mechanism 2 to move a movable portion (described later) of the forming die 1. The press molding is performed by operating the press molding, and the press molding is preferably performed in an inert gas atmosphere such as a nitrogen gas atmosphere. To this end, the mold 1, the press operation mechanism 2, and the like are provided in a molding chamber 3 having an airtight structure.

The molding chamber 3 is disposed on the gantry 10 and is provided with a gate valve 11 at an entrance 301 for carrying in the glass material and carrying out the molded product, and is communicated with the outside via this. ing. Further, a mold exchange chamber 12 is provided on the gantry 10 adjacent to the molding chamber 3, and the exchange chamber 12 is connected to the molding chamber 3 via a gate valve 13. Communicating.

Further, in the molding chamber-3, there is provided a replacement means 4 for introducing a glass material into the molding die 1 and leading out a molded product. The exchanging means 4 attaches a suction hand 402 to the upper end of a rotating shaft 401 which penetrates the floor of the molding chamber 3 and is vertically introduced into the molding chamber 3 from the outside. The rotary shaft 401 is rotatably connected to the piston rod 14A of the cylinder mechanism 14 provided on the gantry 10,
By the operation of the piston rod 14A, the piston rod 14A is moved up and down in the axial direction, and is rotated via a gear train 16 by an electric motor 15 provided on the piston rod 14A. .

When the glass material is sucked on the suction pad 403, the rotation shaft 4 is controlled based on the control of the cylinder mechanism 14 and the rotation control of the electric motor 15.
01, the suction pad 4
03 is introduced into the molding die 1, and is removed from the molding die 1 by the axial operation and the rotating operation of the rotating shaft 401 in the opposite direction in a state where the molded product is sucked by the suction pad 403. Works like that.

The glass material and molded product carrying-in / out means 17 for the molding chamber 3 are arranged above the gantry 10 below the entrance / exit 301. The loading / unloading means 17 is replaced with a piston rod 18A extending upward from the cylinder mechanism 18 and is replaced with a chamber.
171 is mounted, and the replacement chamber -17 is mounted.
1 is provided with a table 172 that can move up and down through an opening 171A at the upper end of the table 1, and the table 172 can be moved up and down by elevating means (for example, a piston / cylinder mechanism) 173 provided in the exchange chamber-171. It is.

When loading or unloading a glass material or a molded product from / to the molding chamber-3,
With the glass material placed on the table 172, the piston rod 18A is raised and the exchange chamber-171 is raised under the control of the cylinder mechanism 18 to open the opening 1 thereof.
71A is brought into airtight contact with the gate valve 11. In this state, the inside of the exchange chamber-171 is replaced with a predetermined atmosphere, the gate valve 11 is opened, and the molding chamber-3 and the exchange chamber-171 communicate with each other.
Further, the placing table 172 is introduced into the molding chamber 3 by the elevating means 173, and the transfer of the glass material and the reception of the molded product are performed with respect to the exchange means 4. Then, thereafter, the elevating / lowering means 173 is operated in reverse, the placing table 172 is returned to the exchange chamber-171, the gate valve 11 is closed, and the cylinder mechanism works.
The replacement chamber-171 is lowered, and the
2 can be taken out and a new glass material can be brought into it.

In this embodiment, a required robot 19 is used to carry the glass material into the placing table 172 and take out the molded product therefrom. The robot 19 is
The glass material is replaced from the stocker 20 with the table 172 by using an adsorption means or the like, and
The molded product is taken out from 72 to a required place. That is, the robot 19 has an X-axis arm 191 and a Y-axis arm 192, and the suction arm 193 provided on the Y-axis arm 192 is moved by the X-Y arm by the action of both arms. It can be moved in the axial direction. In addition, the stocker
20 is provided with an electric motor 20B on a frame 20A,
The pallet 20C is fixed to the rotating shaft, and the pallet 20C is turned by driving the electric motor 20B to receive the molded product and deliver the glass material at a location corresponding to the robot 19. . In this embodiment, a cooling stand 21 is separately prepared, and the molded product taken out of the placing stand 172 by the suction hand 193 is temporarily placed on the cooling stand 21 and naturally or forcibly cooled to a desired temperature. .

As shown in FIG. 3, the above-mentioned molding die 1 has four pairs of a lower die member 101 and an upper die member 102 which are dispersedly arranged in four directions with respect to the center of a molding die 100. It is slidably incorporated and has a four-piece structure. The body mold 100 is used for receiving the glass material by the suction pad 403 and taking out the molded product.
An opening 100A for entering and exiting is formed at the side of the. The barrel mold 100 is arranged and fixed on the pallet 5 in the molding chamber-3. The pallet 5 is provided with a guide rail 6A in the exchange chamber-12.
Through the gate valve 13 from the exchange chamber 12 to the guide rail 6B laid in the molding chamber 3, so that the guide rail 6B is installed at a press position in the molding chamber 3. Has become. Further, the mold members 101 and 102 have flange portions 101A and 1A for limiting the amount of insertion into the body mold 100.
02A are respectively formed.

As shown in FIGS. 1 and 3, the press operation mechanism 2 has a push-up operation member 201 disposed below the guide rail 6B at the press position. Four operating members 202 for pressing are arranged above the mold 1 in correspondence with the respective upper mold members 102, and these are held by a common holder-block 203. The operation member 201 has the upper end thereof in the molding chamber-3.
The molding chamber 3 can be inserted into the molding chamber 3 from the outside via an annular member 204 provided at the bottom of the cylinder.
And a piston rod 206 extending upward from the piston rod 206. A push-up piece 207 common to the lower mold member 101 is attached to an upper end of the operation member 201,
The lower mold member 101 can be commonly pushed up through the lower spacer 101D while sliding with respect to the body mold 100.

The operating member 202 has a stopper at its upper end.
Forming a large-diameter portion 202A for the holder-block 2
03, which is guided by a sliding portion 203A provided at the lower end of the holder block 2 so as to be able to move up and down.
03, the large-diameter portion 202A
Are held downward until they come into contact with the sliding portion 203A. In this embodiment, a structure in which a disc spring is overlapped in the operation direction of the operation member 202 is adopted as the elastic mechanism 208, but other suitable mechanisms and configurations may be adopted. .

A common rod 209 is connected to the upper end of the holder block 203.
Is connected to a piston rod 211 extending through a ceiling portion of the molding chamber 3 and extending from the inside to the outside, and extending downward from a cylinder mechanism 210 for pressing arranged at an upper portion of the molding chamber 3. Have been.

Each of the upper mold members 102 is located at the center thereof, and has a small-diameter contact piece 104 mounted on the top thereof. When the operation member 202 descends, it receives a pressing pressure at its center. It has become. The upper mold member 102 has a flange 10
2B is formed, and the above-mentioned flange portion 102A has
An annular lifting member 105 is mounted. And
A gyro universal joint 106 is provided between the flange portion 102B and the lifting member 105 so that a lifting force acts on the center of the upper die member 102.
Is interposed.

The universal joint 106 is
In particular, in this embodiment, as shown in FIGS.
The pair of hemispherical projection-like support portions 106A and 106B, which are arranged with a phase difference of 90 degrees from each other on a plane orthogonal to the sliding direction of the upper mold member 102, are combined with the upper mold member 102 and the lifting member 105. Corresponding to
The structure is provided on the ring 106C. In addition, an annular spacer 102C is provided between the flange portion 102A and the top of the trunk die 100 in order to regulate the amount of the upper die member 102 falling into the trunk die 100. I have. In addition, an annular spacer 101B is provided on the flange portion 101A in order to regulate the amount of the lower mold member 101 rising into the body mold 100. An annular spacer 101D is disposed between the flange 101A and the push-up piece 207 to regulate the height position of the lower die member 101.

In this embodiment, the hook member 212 attached to the support flange 203B provided at the lower end of the holder block 203 is provided with a claw 212 at the lower end.
At A, the flange portion 105A of the lifting member 105 is suspended. If necessary, as shown in FIG. 5, the lifting member 105 may be integrally formed with the hook member 212.

In the above embodiment, the upper and lower mold members 1
An electric heater (not shown) has been introduced to control the temperature of 01 and 102. Cooling pipes 213 and 214 are provided to perform cooling control on the upper and lower mold members 101 and 102. Also,
The introduction passages 215 and 216 for introducing the cooling medium are provided.
They are formed on operation members 201 and 202, respectively, and communicate with cooling medium introduction portions 101B and 102D formed on upper and lower mold members 101 and 102, respectively. In addition,
In the cooling method for cooling the upper and lower mold members, in addition to the above-described structure, for example, a gas introduction path is provided in the center portion of the holder 203 from the center introduction portion of the rod 209,
The cooling medium is introduced into the upper mold member 201 through a pipe adapter (not shown) provided at the lower end, and the cooling medium introduced through the rod 201 and the center introduction part 215 is pushed up by the push-up piece 207. May be guided to the lower part of the trunk via the center part of the body.

When the glass material is press-formed by using the press operation mechanism 2, first, FIG.
From the state shown in (a), the holder block 203 is raised by the action of the cylinder mechanism 210, and the upper die member 102 is pulled up via the hook member 212, so-called a mold opening. Then, the glass material is introduced into the molding die 1 by the suction hand 402 described above, and the holder block 203 is lowered again. As shown in FIG. Descent up. Thereafter, when the cylinder mechanism 210 is further operated and the holder block 203 is lowered, the operating member 202 is moved via the abutment piece 104 to the upper mold member 1.
A press pressure is applied to the center of 02 (then, the cylinder mechanism 205 pushes up the operation member 201 and presses the lower mold member 101 upward through the push-up piece 207). Therefore, even if there is a clearance required for temperature control in the sliding portion between the body mold 100 and the upper mold member 102, the lower part can be lowered in a state where the posture of the upper mold member is kept vertical. With respect to the direction, there is no displacement of the molding surfaces of the upper and lower mold members 101 and 102, and molding can be performed in a state where the position of the optical function surface with respect to the optical axis of the molded optical element is correctly maintained.

In particular, in the present invention, the common cylinder mechanism 2
10, the upper die member 102 and the operating member 20 are driven because the four sets of upper and lower die members 101 and 102 are simultaneously driven.
2 must be absorbed. However, since the operating member 202 is held by the holding mechanism 208,
As shown in FIG. 4C, after the flange portion 102A of the upper die member 102 hits the top of the trunk die 100 via the spacer 102C, the holder block 203 is further moved.
Can be stopped at that position. For this reason, regardless of the dimensional error, the upper mold member 102 is lowered by a predetermined amount to efficiently (ie, four pieces at the same time) while maintaining the thickness of the molded article with high accuracy.
Press forming of optical elements is possible.

After the molding, the cylinder mechanism 210 is operated to open the mold, and the holder block 20 is opened.
3, the hook member 212 lifts the lifting member 105 as shown in FIG. 4 (d).
The universal joint 106 operates to perform a self-aligning action, so that the upper die member 102 receives a lifting force at its center, so that it does not tilt within the clearance and rises vertically. it can.

The above-mentioned mold exchange chamber 12 is provided with mold exchange means 7. Mold exchange means 7
Is provided with an exchanging means 701 so that the pallet 5 on which the mold 1 is mounted and fixed can be moved along the guide rail 6A into the molding chamber 3 through the gate valve 13. To the guide rail 6B.

The exchanging means 701 has a coupling hand 703 attached to the tip of a rod 702 extending into the mold exchange chamber 12, and an actuator 705 attached to a base end thereof via a thrust bearing 704. The motor 706 mounted on the actuator 705 allows the rod 702 to be rotated via an L-shaped crank 707.
When the actuator 705 is driven, the rod 702 can be moved in the longitudinal direction by moving the actuator 705 along a guide rail 708 arranged in parallel with the rod 702. It is configured.

Then, the rod 702 is rotated by the operation of the motor 706, and the operation of engaging and disengaging the coupling hand 703 with respect to the pallet 5 is performed by this operation, and the operation of the actuator 705 is performed. Then, the above pallet 5
It can move along the guide rail 6A.
Thus, under the control of the exchanging means 701, the pallet 5 is brought to the guide rail 6B of the molding chamber 3 via the gate valve 13 and set at the pressing position of the press operating mechanism 2, or Conversely, it can be withdrawn back to the mold change chamber-12.

The mold exchange means 7 includes pallet replacement means 711 for moving the pallet 5. The pallet replacement means 711 includes a piston rod 71 which advances and retreats in a direction perpendicular to the longitudinal direction of the guide rail 6A.
A cylinder mechanism 712 having 2A is provided on one side of the mold exchange chamber 12, and two stages 713A, 713 are provided at the tip of the piston rod 712A.
A feeder 713 having B is mounted. Each of the stages 713A and 713B is provided with the above-described guide rail 6A. The other side of the mold exchange chamber 12 has an opening for taking in and out the mold 1, and a door 12A is provided therein.

Then, the door 12A is opened in advance, the cylinder mechanism 712 is operated, and the feed base 713 is protruded from the opening of the mold exchange chamber 12 so that, for example, the stage 713A is opened. On the guide rail 6A,
Place the pallet 5 on which the new mold 1 is mounted, and
By operating the cylinder mechanism 712 in reverse,
3 and, as shown in FIG. 2, when the cylinder 12 is biased to the side where the cylinder mechanism 712 is located, the door 12 </ b> A is closed, and the gas replacement in the mold exchange chamber 12 is performed. The guide rail 6A of the stage 713B is located at the center (pallet replacement position) of the mold exchange chamber-12.

Therefore, by the operation of the exchange means 701,
From the molding chamber 3, the used mold 1 together with the pallet 5 on which the mold 1 has been placed can be taken out onto an empty stage 713B. After that, the cylinder mechanism 712 is operated to position the stage 713A at the center of the mold exchange chamber 12, and the exchanging means 701 is again operated to form the guide rail 6A from above. The new mold 1 can be transferred together with the pallet 5 to the guide rail 6B of the chamber-3, and can be set at the press position of the press operation mechanism 2. The used mold 1 can be removed from the pallet 5 by opening the door 12A after replacing the new mold 1 with the molding chamber-3.

Next, the steps of specifically molding an optical element molded article using the above-described press molding apparatus according to the present invention will be described in the order of loading, molding and unloading, centering on the glass material. The optical element molded here is an aspheric lens used for an 8 mm video camera or the like.

The glass material G is a glass blank previously formed into a spherical shape.
Placed on C. Then, by driving the electric motor 20B,
When the rotation axis is rotated by 180 degrees, the robot 19 is operated to bring the suction band 193 to the position, and suck and hold four glass materials from the pallet 20C. Next, the operation of the robot 19 causes the suction band 19 to move.
3 puts the glass material G on the table 172. The glass material on the placing table 172 is preliminarily heated to an appropriate temperature, and is carried into the molding chamber 3 by the operation of the carrying-in / out means 17 as described above.
It is sucked and held by the suction pad 403 of the exchanging means 4 which has been heated to a certain degree, and is introduced into the mold 1. here,
The upper and lower mold members 101 and 102 are preliminarily heated to a temperature of, for example, about 10 ¹⁶ poise in terms of glass viscosity. Then, as described above, the upper mold member 102 is lowered by the operation of the cylinder mechanism 210, and the glass material G is moved to the upper and lower mold members 10.
In the state sandwiched between 1, 102, the glass viscosity is 10 ^{10.5 by} the action of the above-mentioned electric heaters 213 and 214.
It is heated to about poise (the temperature of the lower mold member 101 is about 10 ^9.5 in terms of glass viscosity, and the temperature of the upper mold member 102 is about 10 ^10.0 in terms of glass viscosity).
Is subjected to a press forming under a load of 400 kg. next,
The press pressure is reduced to about 100 kg, and the cooling medium introduction portions 101B and 102D of the upper and lower mold members 101 and 102 are reduced.
A cooling medium is introduced into the glass so that the viscosity of the glass is 10 ^10.5 to 10 ¹³
The temperature is reduced to about poise, where the press pressure is removed. Thereafter, cooling was continued. When the temperature of the molded product reached 10 ^14.5 poise in terms of glass viscosity, the above-mentioned electric heating heater-2 was used.
The upper and lower mold members 10 are controlled by ON / OFF control of the
A temperature difference is given to 1, 102 (to lower the temperature of the upper mold member), the temperature of the molded product is lowered to about 10 ¹⁶ poise in terms of glass viscosity, the upper mold member 102 is raised, and the mold is opened. Then, the molded product is taken out from between the lower mold member 101 and the upper mold member 102 by the suction pad 403.

Thereafter, the molded article is returned to the placing table 172 by the reverse operation of the exchange means 4, taken out of the molding chamber 3 by the carry-in / out means 17, and further removed by the robot 19. By operation, it is temporarily placed on the cooling stand 21, cooled to an appropriate temperature, and taken out.

In the above embodiment, the molding die 1 operates the four sets of upper and lower mold members 101 and 102 in the common body mold 100. However, as shown in FIG. For the members 101 and 102, the structure of the universal joint 106 as described above may be adopted. In this case, the hook member 212 may be directly in contact with one side of the universal joint 106.

[0036]

Therefore, according to the present invention, in a press forming apparatus for forming an optical element by putting a glass material in a pair of mold members, a plurality of the mold members are prepared, and the plurality of mold members are added. When pressure is applied by the pressure means, an elastic member is individually interposed between the plurality of mold members and the pressure means, and the pressure is applied via the elastic member. The optical element can be efficiently press-formed while the thickness of the optical element is maintained with high accuracy, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a press forming apparatus showing one embodiment of the present invention.

FIG. 2 is a schematic plan view of the press forming apparatus of the present invention.

FIG. 3 is a front sectional view showing a main part of the present invention.

FIG. 4 is a front sectional view illustrating an operation state of a main part of the present invention.

FIG. 5 is a front sectional view illustrating a modification of the present invention.

FIG. 6 is a front view of one embodiment of the universal joint of the present invention.

FIG. 7 is a perspective view of the universal joint.

FIG. 8 is a front sectional view for explaining another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 molding die 100 trunk die 101 lower die member 102 upper die member 104 contact piece 105 lifting member 106 universal joint 2 press operation mechanism 201, 202 operation member 203 holder block 208 elastic mechanism 212 hook member G glass material

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-119129 (JP, A) JP-A-64-24027 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C03B 11/08

Claims (3)

(57) [Claims] 1. A molding apparatus for molding an optical element by placing a glass material in each of a plurality of molding dies and individually pressing the mold members of each molding die by a common pressing means.
The mold members of each of the molding dies are slidably arranged on a common body mold, and the pressing operation members corresponding to the respective upper mold members of each molding die can be individually moved up and down on a common holder block. The holder block is provided with a separate elastic mechanism for applying a downward elastic force corresponding to each of the pressing operation members to the pressing operation member. An optical element molding apparatus, wherein when the block is lowered, each elastic mechanism operates at least at a stage where each flange portion of the upper die member abuts on the top of the trunk die. 2. The mold member is slidably held in a body mold, and operating members for operating the upper mold member include:
The press forming apparatus for an optical element according to claim 1, wherein the optical element is held by a common holder-block and is held downward by the elastic member with respect to the holder-block. 3. The press forming apparatus for an optical element according to claim 2, wherein the elastic member has a structure in which a large number of disc springs are stacked in the operation direction of the operating member.